Typically, metallic materials including steel have been used as interior and exterior materials of transportation equipment such as railway vehicles. However, with increasing demand for improved fuel efficiency in recent years, substitution of the metallic materials with plastic materials has been actively studied. There are strict requirements that materials used in transportation equipment have low smoke properties, which allow low smoke generation in the event of fire, to secure passenger safety, and the like.
Polycarbonate resins can have excellent mechanical properties, such as moldability, impact resistance and tensile strength, as well as excellent electrical properties, transparency and the like, and thus are widely used for automobiles, electronics, and the like. Typically, a polycarbonate resin composition is obtained by blending a polycarbonate with an acrylonitrile-butadiene-styrene (ABS) resin, followed by adding a phosphorus flame retardant to the blend. Despite various merits of excellent moldability, heat resistance, moisture resistance, impact strength and flame retardancy, such a typical polycarbonate resin composition is not suitable as a material for transportation equipment due to generation of an excess of smoke upon burning thereof.
For this reason, typically, resins such as polyimides or polyamides have been mainly used for transportation applications. However, polyimide or polyamide resins are expensive and have poor moldability and poorer mechanical properties than polycarbonates.
Therefore, there is a need for a polycarbonate resin composition having excellent moldability and mechanical properties while securing low smoke properties.